I’m having a weird problem with a single stage acetylene regulator I
just purchased for use on an MC tank with my Smith Little Torch. I
installed the regulator following standard protocol, but am having
strange fluctuations in the dials and gas flow. The second dial
(which regulates the actual gas flow) shows the gas pressure to the
torch going up and down from 5 pounds of flow to 2 pounds of flow.
Sometimes it even shows no gas flow to the torch and yet the torch
is obviously getting gas and working just fine. I don’t know if the
diaphram is sticking or what, but it makes for an erratic flame and
I’m concerned about safety.

I’ve also had a couple of occasions when I shut down my torch and
totally bled the lines as usual, only to come back out to the shop
later and find the first indicator dial registering as if I’d opened
the tank to the regulator, (no gas flow through line to torch,
'though.) I’m starting to suspect that I’ve either gotten hold of a
bad regulator or my shop must have spooks. Any ideas?

I had a similar thing happen with a new regulator a while back. I
contacted Smith and they told me to contact the folks I had purchased
it from to have them return it to Smith for a replacement. I’m glad I
called Smith first because the folks I purchased the equipment from
didn’t want to help me until I told them what Smith had said. I did
get a new regulator and have been happy ever since.

Hi Susannah, About 9 years ago, I switched to dual stage regulators
to get more consistent and accurate gas flow. I had studio gremlins,
too, so the dual stage regulators were particularly helpful with the
Little Torch that I often use.

I'm having a weird problem with a single stage acetylene regulator
I just purchased for use on an MC tank with my Smith Little Torch.
I installed the regulator following standard protocol, but am
having strange fluctuations in the dials and gas flow. The second
dial (which regulates the actual gas flow) shows the gas pressure
to the torch going up and down from 5 pounds of flow to 2 pounds of
flow.

Based on the multiple symptoms you’ve described, the safest thing to
do would be to remove the regulator from service. The return it to
the place you purchased it as defective.

It may be fixable, but since it’s new, it shouldn’t need ‘fixing’.
Let the vendor/manufacturer deal with the problem(s).

I have had many problems with the Smith MC regulator. I have gone
through four of them, and eachtime Smith sent a new regulator in
place of the old one. I finally switched to a Uniweld B regulator
with adaptor. You might want to get the one you have replaced and in
the meantime buy a new regulator. The school I teach at uses Smith B
regulators and they have held up well, despite the fact they are not
always shut off properly at the end of class. It seems like the MC
is just a flawed product.

There is something wrong with that regulator as the extreme
fluctuations your experiencing are not normal. I have previously
spoke with Smith on this problem and they stated “there’s probably a
chip on the diaphragm”. The company you purchased it from should
exchange it without a fuss. Smith is a great company that stands
behind their products and will credit the company.

The new single stage acetylene regulator I was having problems with
was made by Victor. When I returned it to my local welders’ supply
place, where I had purchased it, I was told the problems I was
experiencing were the result of a “bad valve seat”, ie., a tiny
piece of trash or a metal shaving preventing the valve between the
tank and the regulator from sealing properly. They replaced it with
no problems, other than the hour I had to shut down production to
drive across town and back.

BTW, I had my old Smith MC acetylene reg in use for 15 years with no
problems until the diaphram began to deteriorate this spring. I
bought the Victor to use while the old faithful Smith was cleaned
and repared (about 2/3 the price of a new unit). At least this way,
I’ll have a back-up.

This community is such a wonderful resource - plus seeing other
folks’ benches has helped me realize mine isn’t so bad after all!